1. Field of the Invention
The present invention relates to a sheet processing apparatus and a sheet processing method and, more particularly, to a folding operation on a sheet.
2. Description of the Related Art
In recent years, there has been a tendency to promote information computerization, and image processing devices, such as printers or facsimile machines that are used to output computerized information and scanners that are used to computerize documents, are essential devices. Such an image processing device has an image capturing function, an image forming function, a communication function, or the like, so that it is often configured as a multifunction peripheral that can be used as a printer, facsimile machine, scanner, or copier.
Out of the above multifunction peripherals, there are known multifunction peripherals that include a folding processing apparatus that, after an image formation is performed on a fed sheet so that an image is drawn, performs a folding operation on the sheet on which the image has been formed.
In this kind of folding processing apparatuses, when a folding operation is performed on a sheet on which an image has been formed, the sheet is conveyed to a dedicated conveyance path for preparing for a folding operation that is to be performed on the sheet, and an end of the conveyed sheet is brought into contact with a stopper that is located on the downstream side of the conveyance path so that a folding position is adjusted and a bend is formed. Then, in the folding processing apparatus, while the sheet is in contact with the stopper on the above-described dedicated conveyance path, it is further conveyed so that the bent portion is guided and pushed into a folding processing unit, and the pushed bend on the sheet surfaces is nipped by the folding processing unit, whereby a folding operation is performed (see, for example, Japanese Patent Application Laid-open No. 2006-117383).
As described above, conventional folding processing apparatuses have a problem in that the above-described dedicated conveyance path or stopper is needed, the space for installing them is needed so that the size of the apparatus is increased, the number of driving systems or control systems for driving them is increased so that the apparatus becomes complicated, and the initial costs and running costs are increased.
In view of the above problem, there is a need to provide a folding processing apparatus that performs a folding operation on sheets with a small-sized and simple configuration at low costs.